Hydraulic gear shifting mechanism



Aug. 20, 1935. w. G. HoELscHER ET AL 2,012,034

HYDRAULIC GEAR SHIFTING MECHANISM Filed Nov. 28, 1930 8 Sheets-Sheet 1 Aug. 20, 1935. w. G. `HoELscHL-:R ET AL 2,012,034

HYDRAULIC GEAR SHIFTING MECHANISM v Filed Nov 28, 1950 8 Sheets-*Sheet 2 BY mTToRNEYs Aug. 20, 1935. w. G. HoELscHER Er AL HYDRAULIC GEAR SHIFTING MECHANISM 8 Shets-Sheet Filed NO v.' ze, 195o monnaies Aug. 20, 1935. w. G. HoELscHER Er AL 2,012,084l

HYDRAULIC GEAR SHIFTING MEGHANISM Filed Nov. 2s, 1930 s sheets-snet 4 Mzfmh,

Aug. 20, 1935. w. G. HoELscl-IER ET AL 2,012,084

HYDRAULIC GEAR SHIFTING MECHANISM Filed'Nov.v 28, 1930 8 Sheets-Sheet 5 Aug. 20, 1935. I w. G. HoELscHE'R AL l '2,012,084

I HYDRAULIC .GEAR SHIFTING MECHNISM I Filed Nw..v 2s, 195o ashevetsfsheet e Augf 20, 1935. w. s. HoELscHER ET AL y HYDRAULIC GEAR SHI-FTING MECHANISM Filed Nov. 28, 1930 8 Sheets-Sheet .Nw .mwN

W. G. HOELSCHER ET AL- HYDRAULIC GEAR SHIFTING MECHANISM Aug. -20, 1935.

Filed Nov. 28,'1930 8 sheets-sheet 8 NNN Patented Aug. 20, 1935 UNITED STATES PATENT OFFICE "2,012,084 A HYDRAULIC vGEAR SHIFTI'NG- MECHANISM y Application November 28, *1930, Serial No. 498,654

14 Claims.

This invention relates to lathes and is'particularly directed to a fluid operated gear shifting mechanism for varying the speed of rotation of the spindle shaft of the lathe including the structure and arrangement of the control devices for selective hydraulic gear changing.

It is an object of this invention to provide `a hydraulic mechanism for shifting the speed change gears lin the headstock, which mechanism, including various gear sliding devices, a pump for creating the fluid pressure', and the control devices, is entirely located in the headstock; and wherein the gear shifting control for selectively varying the spindle speeds is conveniently and accurately operable by means of a manipulating indicator dial. It is furthermore an object to provide that the iiuid pressure within the headstock which is circulated throughout the hydraulic system is constantly maintained at a degree of pressure suitable for shiftingthe gears by virtue of the power connection for the pump, wherein the pump is driven from a constantly rotating shaft, that is, one which is primarily moved by the power source for the lathe.l It is alsoanobject to provide that after the control dial is reset to the appropriate speed as indicated, the gear shift or speed change is eiected automatically and immediately upon the power being connected. 'I'he speed changes thus accomplished are maintained without any opportunity for mishandling or improper gear shift sequence, since `point a more eilicient control of the lathe ishad forfregulating the speed and length of traverse .fof lthe carriage and the depth of the out. It has been usual, in lathe design, to include a dual power lcontrol for the spindle enabling the operator to connect the power either by means of nipulating indicator dial located on the head' 4 lathe construction and which has resulted in considerable labor and inconvenience on the part of the operator has been the fact that the face plate mounted on the spindle, which element must be rotated by hand during the processes of fastening the parts to be meshed thereto, has been incapable of total disconnection from the gearing, wherefor rotation thereof has compelled a back rotation of all the gears in mesh at the particular time. It is, therefore, an object of` this-invention to provide a transmission, which is hydraulically shifted, including a free spindle position whereby in addition to the speed changes, such as sixteen in the average lathe, for associating therewith a seventeenth position in which the gears directly driving the spindle are disconnected or unmeshed when it is desired to manipuiate the face plate. It will readily be seen that this free spindle position is of extreme importance in any type of transmission, and isiof special importance vin the instance of hydraulic shifting wherefor the hydraulic control accomplishing this positioning of the gear train includes devices of particular construction and in novel arrangement.

It is another object of this invention to provide fluid pressure gear shifting means including a primary or main control associated with the power control clutch, terminating the fluid pressure iiow tothe gear shift selector valve coincidentally with the unclutching of the power to the gears, whereby the selector valve may be reset for the desired speed change. The one duration from the foregoing operation occurs atthe seventeenth or free spindle position, it being vprovided at this position that the fluid pressure now is admitted through the selector valve for disengaging the appropriate gears.

Another object is to provide a uid pressure means associated with the transmission of a lathe for changing the gears which also combines the lubrication system for oil'ing the bearings of the transmission, the lubrication system making use of the overow or'surplus fluid pumped from the motor and overflowing or being relieved from 50 the pressure head necessary to maintain the selected gears in mesh.

Another object is to provide a hydraulic gear shifting syst/em of the nature described in which the iluid used for shifting and oiling purposes the lathe and carries a face plate or work point on an end extended beyond the connes of the headstock. The shaft is journalled in bearings A in the walls of the headstock casing and the power has been applied at various points along the spindle shaft length within the headstock.

The present invention further relates to an improvement in the application of the drive to the spindle shaft and has for another object the provision of a power transmission which imparts the drive to the spindle at points as nearly adjacent the bearings. thereof as possible. The purpose of this construction is to eliminate springing of the spindle shaft under the driving impulses such as woul occur if the drive were imparted exactly intermediate of the shaftlength or at a distance from the bearings. This springing results in disalignment of the work since the face plate or work point is thrown out of axial alignment with the tail-stock point, its axial po.

sition varying considerably as the shaft rotates. With the driving gears on the spindle mounted shaft is maintained despite heavy driving pressures.

Other objects and certain advantages relate to the construction of the selector valve for controlling the uid flow from a common point of head pressure to the respective shifting devices as well as the construction of the shifting devices and appropriate interlocks for preventing improper intermeshing of gears, which objects together with certain other objects and advantages will be more fully apparent from the description of the accompanying drawings, in which:

Y. Figure 1 is a general perspective view showing an entire lathe and illustrating the respective dual arrangements of the power control devices and the speed change control devices as well as the association of respective ones of these arrangements for speed change and power control either from the carriage or the headstock.

Figure 2 is a longitudinal sectional view taken through the selector valve, illustrating its mountnecting the manipulating knob onl the carriage to the longitudinally disposed splined shaft.

Figure 5 is a fragmentary sectional view taken transversely of the headstock at the point of the clutch for illustrating the relation of the main control valve and the uid pressure pump relative to the clutch and its operating mechanism and a constantly rotating gear on the main power shaft of the headstock.

' riage.

Figure 6 is a fragmentary view taken on line 6 6, Figure 5, further detailing the relation of the fluid pressure pump to the main power shaft and also showing the power pulley for the headstock gearing.

Figure 7 is a diagrammatic view illustrating the vcomplete hydraulic system and showing the various gear shifting devices and the selector valve in set-position for operating the spindle at lowest speed, a series of transverse sections of the selector valve being included for illustrating the conduit connections.

Figure 8 is a diagrammatic view taken similar to Figure 7, but showing the clutch in neutral position and the selector valve and various gear 4 shifting devices of the hydraulic system set for the neutral, seventeenth, or free spindle position. Figure 9 is an enlarged longitudinal sectional view of the rotatable,=element of the selector valve.`

Figure 10 is a developed view of the peripheral surface of the rotatable valve element, illustrating in detail the variousI grooves therein and the supply ports entering the interior of the rotatable valve element.

Figures 11 to 19 inclusive are transverse sectional views taken on the respectively indicated lines of Figure 9, for illustrating the relation of the grooves and ports of the valve to the respective conduits extending 'to the shifting devices when the selector valve is in free spindle position.

Figure 20 is a diagrammatic view illustrating the complete hydraulic gear shifting system in,

relation to the spindle operating transmission of the lathe, this view being similar to Figures 7 and 8, but showing the apparatus and transmission in position for imparting high speed to the spindleV shaft.

Figure 21 is a longitudinal sectional view, enlarged-out of Figure 20, of the rotatable element of the selector valve. l

Figures 22 to 30, inclusive, are transverse'sectional views taken on the respectively indicated lines of Figure 2l, for illustrating the relation of the grooves and ports of the valve to the respective conduits extending to the shifting devices when the selector valve is in high speed position.

Figure 3l is a diagrammatic view of a portion of the transmission, including various. sectional views of the selector valve for showing in detail the hydraulic shifting vapparatus about to be shifted to neutral or free spindle position after the transmission has Vbeen at low speedl the view being provided for the purpose of illustrating in detail the hydraulic interlock and the particular gears affected by the selector valve in free spindle position.

'I'he present invention, described in general and as applied to the spindle speed change gears of a lathe, discloses the entire hydraulic gear shifting apparatusincluding the fluid pressure supply means compactly assembled within the headstock of the lathe. The selector valve for directing the pressure ow" to the selected gear shifting device is also located within the headstock but is manipulated from the exterior thereof at two points by means of duplicate speed control devices. One of these is located on the headstock and the other is mounted on thecarform of dials suitablyindexed to indicate the various speeds applied to the spindle through the dial settings. The present arrangement of dials or control devices for speed change includes a dial adjacent each power control lever for the The ultimate control devices are in theA application of hydraulics to the gear shifting drive to the headstock gears, there being a lever headstock and one on the carriage, these levers connected to the clutch for arbitrary use as convenient for the operator.

These levers which operate the clutch connecting the power pulley to the transmission also operate a main control valve in the vheadstock which admits the fluid under pressure from the pump to the selector valve when the clutch is in. When the clutch is out or disconnected, the control valve iseffective for admitting the iluid pressure flow from the pump to the selector valve, in one position of theselectorvalve, for an entirely different purpose from that of the gear shift effecting connection of the flow when the clutch is connected, namely the general unmeshing of all the gears connecting the power directly to the spindle .andthe accomplishment of the free spindle or neutral position. The selector valve is shiftable only at the time lwhen the clutch is disconnected andis, therefore, capable of setting, at this time, for effecting the neutralizing shifts of the various shifting devices associated with the gears of the train.

The control valve also admits fluid from the selector valve to the stand-pipe when the clutch is disconnected for permitting relief in the various passagewaysand central bore of the selector valve, any overow of oil from the stand-pipe taking place into the casing reservoir. The exhaust from the various shifting devices during reversal of pistons take's place directly from the selector valve through an outlet port emptyinginto the lower regions of vthe headstock casing. Therefore, the ow of pumped fluid under pressure to the selector valve lmay be accomplished through either position of the control valve, as determinedby clutch position in the instances' of clutched position for gearchange and in the rious pipe conduits, connecting the various shifting devices to the casing, for the accomplishment of the various shifted positions of the gear train. The fluid pressure is thus manually controlled from the point of the selector valve ufor introduction to vthose shifting devices effecting the desired gear change and for appropriate exhaust'. The pipe connections from the selector valve to the shifting devices may function as feed lines, discharge lines, or may be shut olf at the valve to trap the fluid therein and lock the particular devices previously shifted. In those instances, in the 'particular transmission disclosed, where two gear clusters are independently shiftable on the same shaft, a hydraulic interlock is provided between the sluiting devices, operating respective gear clusters, being devices is secured within the headstock upon a side wall-thereof (see Figure 2). 'I'he selector valve is of a rotatable type including (see Figure 2) a stationary casing 40 which is secured to the wall anda rotatable element 4`I contained within the casing having a stud or shaft portion 42 extending through' the headstock casing wall to the exterior thereof and carrying a 4knob 43 keyed thereon and Aheld in place against axial displacement by means of a screw 44. This knob includes a dial 45 graduated to represent seventeen positions, in the present instance, the graduations on the dial adapted to indicate the particular position of the gears as determined by registration of one of the graduations with a mark on the headstock wall.

A second means is provided for rotating the element 4| of the valve from the carriage. For this purpose a bevel gear 46 is secured on the shaft extension 42 of the rotatable element between the knob and the element proper. This gear 46 is in mesh with another bevelled gear 41 of the same size secured to the upper end of a vertical shaft 48 supported in and extending downwardly (in this instance) through the headstock and lathe bed. Another bevel gear 4Q is secured on the lower end of this vertical shaft and is in mesh with another bevel gear 50 fixed to a splined shaft 5|, disposed longitudinally of the lathe bed and iournalled in brackets thereof, the latter gear 50 being pinned to the shaft against rotative andlon'gitudinal displacement.

The carriage 36 has a vertical shaft 52 rotatively journalled therein and a knob 53 including a dial 54 is mounted on the upper end of theshaft v52 and is disposed for movement relative to a mark on the top surface of the carriage. This knobis identical tothe knob on the headstock. A bevel gear 55 is secured on the lower end of the vertical shaft 52 in the carriage, this gear 55 being in mesh with a bevel gear 56 slidably vmounted on the splined shaft 5l and has its sleeve or hub extension rotatively journalled in a depending bearing extension 51 of the carriage. There- `fore, as the carriage is traversed, the gear in ,splined connection with the shaft slides along the same and is capable of transmitting Y'rotative movement to the shaft at any position of the carriage for rotating the valve element through the aforesaid connection for accomplishing the same settings of the dial and appropriate gear shifts as those accomplished by manipulation of the knob on the headstock. It is, therefore, possible for the operator to change spindle speeds either from position at the carriage or at the headstock.

Each of the selecting knobs 43, 53, is definitely associated with a power control lever. As one means for this purpose a fulcrumed power control lever 58 is mounted on the headstock, the handle end of this power'control lever extending to a point adjacent the speed change knob 43 on the headstock.

The short arm of the fulcrumed lever 58 is connected, by means of a link 59, to one arm of the bell crank lever B pinned to the clutch operating shaft 6 I journalled in the walls of the headstock. It will also be observed at this point that the cam 62 for operating the main control valve 63 of the hydraulic gear shifting system is also pinned to this clutch operating shaft 6I (see diagrammatic views and Figure l) The othervarm of the bell crank lever 60 is connected by means of a downwardly extending link 64 to one arm of a bell crank lever 65 pivoted on the lathe bed, the other arm of the last mentioned bell crank' lever being connected by means of a third link `66 to the swinging end of an arm 61 pinned to a splined shaft 68 which extends longitudinally of the lathe bed, adjacent and parallel lto the speed change control shaft 5|.

'I'he power control shaft is journalled atythe respective ends of the lathe bed in the same manner as the shaft 5| and traverses a bracket 69 of the carriage this bracket carrying a second power control lever 18 rotatively journalled therein and extending upwardly to a point adjacent the knob 53 on the top of the carriage. Y

The lever 10, including its sleeve orhub extension, is slidably mounted on the splined longitudinally disposed shaft 68 for the purpose of imparting rotative movement to the shaft when the lever is moved, and at the same time permitting longitudinal movement of the carriage carrying the' lever along the shaft. 'Ihe lever.

58 and knob 43 and the lever 10 and knob 53, therefore, are conveniently accessibly associated for control of the power and operation of the selector valve for speed change either from the carriage or the headstockl The hydraulic system has been illustrated in diagrammatic or lay-out form. It is to be understood, however, thatit is preferable to mount all of the mechanisms for shifting the gears, including the power, within the headstock. Sufficient portions of the headstock casing and its contained parts and gears aredisclosed in the diagrammatic views in combination with the fluid operated gear shifting apparatus to disclose this feature of compact assembly. g

The gear transmission, to which the hydraulic shifting means has been applied in the present instance, accomplishes the various speed changes for the spindle shaft 1| of -the lathe.

I.The face plate mounted on the spindle shaft 1| is indicated at 12 (see Figure 1 and diagrammatic views) and the power transmitted to this face plate through the various gears and shafts of the transmission is provided through a motor driven pulley indicated 'at 13, nreversal and disconnection of the pulley from the transmission transmission so that it is extremely easy to rotate the face plate 12 on the external end of the spindle shaft by handwhen the work is being placed in position or manipulated. I'he details "through gearing and an intermediate shaft 16. Y

The rst shaft, 15 or the one'directly driven by the pulley carries two gear clusters 11, 18, each of which has two gears formed thereon, theseVV gears being splined on the shaft and shiftable by respective hydraulically operated devices 19, v8|). The size ofthe four gears 11, 11b, 18, 18h, thus carried by the first shaft is graduated. As will be disclosedlater, the two hydraulic devices 19, 80, for shifting these gear clusters on thesame shaft are hydraulically interlocked so as 'to prevent the shifting of one while the other is in mesh.

Adjacent these shiftable gears are four gears 8|, 82, 83, and 84, respectively component to the gears on the shaft 15 and keyed to a sleeve 85 rotatively journalled on ball bearings on the intermediate shaft 16. that four speeds may be imparted to the aforesaid sleeve 85.' The sleeve carrying the four gears on the intermediate shaft has a gear 86 formed thereon, this gear being engaged by the rst of two gears 88a, 88h, contained in a cluster 88 slidably keyed to a sleeve'89 rotatively journalled on the spindle. cluster last mentioned is adapted to mesh with the smallest gear namely 8| of the four gears on the sleeve of the intermediate shaft. A. hydraulically' operating shifting means 90 is provided for shifting this cluster 88 for alternate mesh with the gear 86 integral with the, loose sleeve of the intermediate shaft and the small gear 8| of the four gear cluster keyed to the sleeve. Thus it will be apparent that eight speeds may be imparted tol the spindle through the arrangement described up to the present point.

The sleeve 89 mounted for loose rotative movement on the spindle shaft is connectable to the spindle shaft by means of a hydraulically operated shifting device, which device will be better described at a subsequent position in the description. i

The loose sleeve 89 on the spindle shaft has a 41 gear 9| formed on its end, which gear is in constant mesh with a large gear 92 xedto the intermediate shaft 16. The intermediate shaft 16 carries a small gear pinion 93 in splined connection therewith and slidable by means of a hydraulically operated shifting device 94 for meshing with a large gear 95 keyed tothe spindle.

Thus it is possible through the back gearing represented by gears and 9| on the intermediate shaft, to impart eight speeds to the intermediate shaft. For transmitting the eight speeds imparted to the loose sleeve 89 on the spindle shaft directly to the spindle, an internal gear element 96 is splined to the hub of the large gear 95, keyed to the spindle, for mesh with a gear 81 formed on the end ofthe sleeve 89, the shifting.

of this gear 96 being accomplished by means of a hydraulically operated shifting device 99.

The'spindle shaft is journalled in the walls of the casing in roller bearings and extends through 'the forward wall of the casing. The faceplate 12 'is mounted on the extended end of the spindle vfor carrying theV desired work or for carrying a work point if desired.

'I'he spindle shaft is journalled in roller bearingsin the end walls of the headstock casing. The gears 88s, 88h, 9| and 95, which are mounted on the spindleshaft for the purpose oftransmitting power thereto, are located adjacent the bearings which journalthe shaft. The gears 88,

, 88h, and 9|, through which the power is transmitted to the sleeve 89, loosely mounted on the spindle shaft, and thence transmitted to the intermediate shaft, are located as nearly adjacent the bearing at that end of the shaft as possible. Likewise, the gear which is keyed to the spindle shaft at the forward end thereof, is located close The other gear 88b of the.

up to the bearing journalling the forward end of would be the case if the gears were located at the central or unsupported part of the spindlei shaft. Any springing of the spindle shaft disaligns the axis thereof displacing the work point or the work plate and causing inaccuracy in the work. The thrusts therefore are taken close to the supported parts of the shaft with the iresult that springing of the shaft is practically eliminated. I f

The foregoing arrangement of gears, therefore,

is suitable for imparting sixteen speeds to the spindle. It is obvious that the present hydraulic gear shifting system can be readily appliedA for any number of gear shifts, the present transmission being arbitrarily selected as representing a typical environment.

The pump |00 for developing the iluid pressure for shifting the gears is driven from the constantly rotating shaft upon which the driving pulley and clutch are disposed.

As shown in Figures 5 and 6 a substantial oil levell is maintained in the bottom of the headstock transmission casing and this oil is free to flow through a port |0| into the casing compartment housing the reversing gearing and clutch 'i4 for the main power control. 'Ihe pump |00 is mounted in this casing and is driven by means of a gear |02, mounted on a shaft extension of the pump, in meshiwith a gear |00 mounted on a constantly rotating power reversing shaftl |04 of the reversing gearing driven through a pinion |05 and gear` |06, the latter gear being mounted on the power shaft section carrying the pulley 13. The pump draws the oil through a screen intake |01 and delivers it lthrough a. supply conduit |08 extending tofthe main control valve 63. Through this power connection for the pump, as long as the main power to the lathe is on, the pump will continue to function and deliver a fluid pressure to the control valve where, in the event the control valve is in position to cut oil the flow, the oil will be delivered through a relief valve |09 '(see diagrammatic views), then to a lubricant reservoir ||0.

The control valve is mounted in a boss formed in a wall of the headstock casing. Under all conditions of operation, the iluid delivered under pressure is blocked or obstructed in the selector valve, the purpose being to maintain a pressure head in the selector valve, whichvalve controls lthe delivery to the hydraulically operated shifting devices 19, 80, 90, 94 and 99. The constantly maintained fluid pressure is effective for holding the particular parts in certain deflnite shifted positions, and is relieved over a certain pressure through the relief valve |09 and conduit to the lubricant reservoir 0. The reliefvalve |09 lovcatedin this line is of a type readily arbitrarily set to relieve at any desired pressure, the relief in the present case occurring when the pressure head is developed above that sufcient for operating the various devices.

The lubricant reservoir is located above all of the bearings ofthe transmission and, therefore,

in the upper regionef the headstock. Various of conduits ||2, I3 extending from Vthe control valve to the selector valve 39. The positions of the control valve are determined by the positions of the clutch, there being two positions corresponding to the clutched and unclutched positions of the clutch regardless of direction of drive.

The two conduits extending to the selector valve are for two distinct purposes. The one namely 2 which is connected vto the main supply, when the clutch is out, is for the purpose of establishing the neutral or seventeenth position of the gear transmission; whereas the other namely I3 is for the purpose of delivering the fluid under pressure to those particular gear shifting devices which are in communication with the main chamber of the selector valve as determined by the set position thereof.

'Ihere is still a fourth connection to the control valve, this beingv in the form of a stand-pipe ||4 which is connected to the main chamber of the selector valve when the clutch is out for permitting a gravity feed of the fluid in the stand-pipe directly to the system for constituting, in the event of leakage, a reserve fluid supply when the pump is idle due to non-use of the lathe. Furthermore, the interior of the valve is thus opened through thev stand-pipe for releasing the hydraulically operated detent therein and permitting resetting Yof the valve when the clutch is out-or in neutral., The stand-pipe has an open reservoir ||4 secured on its upper end.

The mechanism for operating the control valve and the structure4 of the control valve are of the following nature. The cam segment 62 mounted o n the operating shaft 6| of the clutch has its peripheral surface in engagement with a roller l5a on the upper end of the moving element or plunger ||5 of the control valve 63. 'I'he cam is symmetrical having a central notch ||6 therein,

which notch receives the roller of the valve plunger when the clutch is in neutral position.

The plunger is urged upwardlyv by means vof a spring for causing the plunger to move de-` pending on its contact with the periphery of the cam. The respective side portions of the caml induce downward movement of the plunger in either Y forward or reverse drive of the transmission. The plunger intermediate of its length includes annular grooves ||8, ||9 spaced apart and alternately registering with the inlet port for the supply conduit |08 which extendsradially into the valve casing.

The conduit I2 extending from the control valve 63 to the selector valve 39 for establishing nects the mentioned conduits |08 and ||2. This position of the control valve,A as has been described before, occurs during the unclutched position and the conduit ||3 is connected to the stand-pipe |20 through the groove ||9. The stand-pipe is connected to a longitudinal groove |20a in the valve casing internal wall surface connecting with the upper groove' ||9 at the mentioned position. l

Rocking of the cam 62 in either direction for forward or reverse power transmissions and de-f pression of the plunger connects the main supply conduit |09 with the conduit ||3 extending to the central chamber of the selector valve since the upper groove ||9 is moved into registry with these two conduits |08, H3, the stand-pipe ||4 and the conduit ||2 'extending to theselector valve for neutral position vbeing cut oil'l at this time.

Figure 8 of the drawings is illustrative of the unclutched position of the transmission since it shows the apparatus in neutral or seventeenth position.

The selector valve has its casing 40 supported in a bracket l0 (see Figure 2) attached internally oi and to the head-stock casing for accommodating a dual rotative connection to the valve element 4| as previously described.

The rotatable element 4| of the valve has a plurality of grooves formed therein v(see Figure 10) i The conduit ||3 extending from the control valve to the selector valve, which conduit is connected to the iluid pressure means when the clutch is in, communicates with a regular annular groove |2| in the periphery of the rotatable valve. element, being in constant registry with this annular 'I'he annular groove |2| communicates with the interior of the rotatable valve element through a plurality of radial ports |22.

A hydraulically operated detent |23 is longitudinally slidably mounted within the chamber of the rotatable valve element, being urged toward the rear end ofthe valve by a spring |24 under compression between the closed opposite end of the valve inner chamber and a bore within the detent.

for the/particular shifting devices eiecting the sixteen speed changes. 'I'he second set or that set atV the left hand end of the valve as shown, is inclusive of -ve groovedtransverse planes of the rotatable valve element, and this group is for ,.5 the purpose of controlling the seventeenth or free spindle position.

'I'he rotatable valve element has seventeen rotatable positions, the positions being determined by the number of teeth on the detent and therel0 fore making it possible to accuratelyA set the dial for any one of these seventeen positions by moving the rotatable valve element the desired number of teeth.y 'I'he nrst mentioned group of grooves are interconnected to make up a contiuu-v 15, ous passageway |28 (seeFigur-e 10) and exhaust throughf common exhaust ports in thecasing. In the same sections of the valve are radial supply ports extending from the periphery of the rotatable valve element into the interior chamber 20 thereof. These radial supply ports are arbitrarily registered with radial ports in the valve casing connected by conduits to the particular shifting devices. 'I'he irregular grooving |28 constituting a continuous passageway for exhausting purposes, 25 registers with the conduits coming in from the respective shifting devices for exhaust at ap- I propriate times, the exhaust taking place through a plurality of radial passageways |29 in the casing extending to the exterior thereof and adapted 30,. to deliver the exhausted uid to the lower region of the headstock where it is repumped back into the system. For the' purpose of clarifying the description, the second mentioned group of openings and grooves accomplishing the seventeenth 3.5

The head end ofthe detent |23 includes a series orneutral free spindle position will be omitted of teeth adapted to engage` with teeth formed on the inner face of an end cap |25 of the valve casing. The head |26 oi' the slidable detent nts into a cross slot |21 in the end of the rotatable valve element for the purpose of 'connectingY the detent and valve element unitarily non-rotatively within the casing when the teeth of the detent are meshed with the teeth of the cap |25. The number of teeth on the detent corresponds to the number of selector valve positions, as seventeen in this case. A

The radial supply ports |22 extending inwardly from the annular groove |2| are continued through the detent and enter the interior of the rotatable valve element via the'spring receiving' bore of the detent. The communication between the conduit entering the annular groove and the interior of the valve is constant and it is, therefore, obvious that the uid pressure is either supplied to the central chamber or exhausted there- .from depending on the position of the clutch.

When the uid pressure is supplied and during power transmission, the detent is 4locked in -supplies or exhausts the interior of the valve,-

the exhaust being for purposes of detent release and valve chamber connection to the st and-pipe, there are two other sets of grooves in the periphery of the rotatable valve element. The ilrst Vgroup cf grooves, at the. right hand end of the valve as shown, is disposed in the firstve transverse planesof the rotatable valve element, and

with radial supply ports in the movable valve element is designed for controlling the' delivery, exhaust, and trapping of the iluid under pressure until the full description of the. means for accom- J plishing the speed changes has been given.

Extreme low speed transmission The-extreme low speed position of the valve and resultant shifted positions of the gears and shifting devices will be set forth in the iollowing description detailing the structure of the selector valve and the shifting devices. This position has 5,

been diagrammatically illustrated in Figure 7. For the purpose of disclosing the exact structure of the selector valve, reference is also made to Figures 9 and 10. 'Ihe valve element development shown in Figure 10 is taken or worked from a line 50 coincidental with the principal pipe connections controlling neutral position or seventeenth position.

'Ihe developed view illustrates the interconnected exhaust grooves |28 for exhausting through 55 22) extend to the two shifting devices 19, 89, re- 65'- spectively controlling the shifting of the two gear clusters 11, 19, on the first shaft 15 of the trans,-4 mission. The conduits extending from the third transverse sectional plane of the valve (same as Figures 12 and 23) also control the operation of 70 these mentioned hydraulic shifting devices 19, 80. In the second transverse plane of the selector valve the rotatable valve element includ'es four radial supply ports |32 extending from its interior. These four ports are arranged substan- 75,

tially .90 apart and one thereof is adapted to register in low speed position with a-supply conduit |33 extending to the hydraulic shifting device 80 of the large gear cluster 18 through its particular interlock meansand thence to the hydraulic shifting device 13 for the small gear cluster 11 for shifting the same and meshing the smallest gear 11* of the small gear cluster with the large gear'84 of the group of four on `the intermediate shaft 16.

It is necessary at this time, to positively balance thefirst mentioned shifting device 80 in.

neutral or intermediate position whereby the gears of thecluster controlled thereby are held out of mesh in order to permit passage of fluid 'through the interlock. For this purpose a supply conduit |34 extends from the third transverse plane of the selector valve. In the instance 'of the third transverse plane there are eight radial supply ports |35 in the rotatable valve element arranged in groups of two at substantially 90 apart;

In the position described, one of the supply ports |35 of a group is in registry with the supply conduit |34 previously mentioned. This supply conduit |34 is forked to extend to both ends of the shifting device 80. Each of the respective forks enter the region of a cylinder |36 at the rear of a floating piston |31. The floating pistons in this position are engaged against the respectively adjacent ends-of a shifting plunger |38 carrying a yoke element |39 in engagement with the gear cluster 18. Each floating piston |31 includes plunger contacting extensions |40 of larger diameter than the plunger |38 and of smaller diameter than the piston |31, there being an extension |40 at each end of the floating piston for constituting the abutment means engaging the ends of the cylinders for providing clearance around the ends of the pistons when they are urged against the ends of the cylinders and the plungers.

The shifting plunger is of a length corresponding exactly to the distance between the adjacent ends of the cylinders housing the respective floating pistons so that the introduction of fluid pressure behind the floating pistons effectively balances the plunger in intermediate position. An interlock plunger |4| .is pinned to the shifting plunger and yoke element and slides in the cylinder bodies above the floating piston cylinders. Each end of the interlock plunger has an annular groove I42therein, these grooves being adapted to control, by registration, the respective supply lines extending to -the presentlyl actuated shifting device 19. v

Referring again to the supply conduit |33 for the shifting` device 19 effecting the present gear shift, it will be noted that the annular groove |42 at the particular end of the interlock plunger overlaps the respective radial ports |43 of the respective sections of conduit |33 adapted to be coupled. These ports are clrcumferentially placed at 90 apart so as to permit convenient attachment and overlapping by the annular groove in the interlocked plunger. Therefore, this supply conduit |33 is connected to the shifting device 19 of lt's shifting plunger opposite to that being supplied aswell as being exhausted at -the side of the floating piston opposite to that into which the fluid is being introduced. Therefore, a conduit |44, same as balancing supply conduit |34 but functioning as an exhaust, extends between these two cylinder ends and the selector valve casing, the conduit entering into the third transverse plane of the valve'and connecting with a circumferential fork of the main exhaust passage |28 in the rotatable element of the selector valve and thence exhausting through the radial ports |29 in the casing to the reservoir.

'I'he cylinder of -the shifting device 19 toward. which the shifting plunger is being moved, is also exhausted on the side opposite to that exhausted through the conduit |44, this exhaust taking place -through a conduitA |46 extending to an interlock groove of the shifting device 80 and thence through the aligned groove, aligned with the conduit sections, to the selector valve casing and thence through another circumferential fork of the exhaust in the second transverse Plane of the valve.

Prior to the shift of` the shifting device 19, the forward ends of the respec-tiveL Boating piston cylinders of the device 80, being balanced or moved into neutral, are exhausted to permit the coincidental plunger balancing movement of the floating or balancing pistons. Therefore, from each cylinder of the device 80 respective conduits |48, |49 extend to the respective annular grooves of the interlock plunger on the shifting device 19, this interlock plunger being moved into intermediate or balanced `position prior to the shift to low speed position. These conduits |48, |49 are connected to the valve in the secondv section of the valve and are in registry with a fork of the exhaust vgroove |28. As soon as the balance has been obtained in 'the shifting device 80, it will be seen that the supply and exhaust ports are properly arranged for operation of the shifting device 19 in either direction. This is true of both shifting devices 19, 80, the shifting of one depending on the balanced position of the other. The described gear'shift effects the first of a. series of gear changes occurring simultaneously through one setting of the selector valve for the low speed drive to the spindle.

For the purpose of the second change of this speed, the shifting device 90 engages the gear cluster 88 slidably mounted on the gear sleeve 89 mounted on the spindle shaft 1|. The shift in this instance causes meshing of the large gear 88a of the cluster with the small Agear 86 loosely mounted on the intermediate shaft so that the mounted in the headstock casing wall and a plunger |5| within the cylinder, the plunger having a yoke |52 pinned 'to its'extending end and the yoke slidablymounted on a stud |53 secured in and extending from the casing wall, the yoke engaging the gear cluster 88. 'The plunger |5| includes an enlarged diameter portion or head |54 `slidably mounted in the cylinder and a smaller diameter portion extending through a sleeve insert |55, secured in the end of the cylinder, for

carrying the yoke. The head at its outer end has a reduced diameter portion |56 providing an extension for abutting the end of the cylinder, the

groove permitting the entrance oi' fluid under pressure againstthe head of the plunger even For shifting the gears at this time, the fluidV under pressure is introduced against the inner end of the head about the small diameter portion of the plunger. 'I'he entrance of fluid under pressure is made easier by a chamfered inner end of the sleeve insert |55 providing clearance at the iluid entrance when the inner end of the head is abutting the sleeve. The fluid vis introduced at this point by means of a conduit |51 extending from the fourth transverse plane of the valve and in registry at this time with 'one of a lseries of supply ports |66. These ports are arranged at substantially diametrically opposite sides of the valve in groups of four. 'I'he other end of the cylinder or the region at the outer end of the plunger head is exhausted through a conduit |59 extending to the fourth transverse plane of the valve and exhausting through a fork of the main or common exhaust groove |29.

'This shifting device 99 has only two positions, both of which are positions of gear lengagement and therefore does not include the balancing orl oating pistons or interlock means included in the first two shifting devices 19, 80.

From the point of this gear engagement, the

- drive proceeds through the loosely mounted sleeve I9 by way of its end gear 9| which is a small gear in mesh with the large gear 92 keyed to the intermediate shaft whereupon the intermediate shaft drives the spindle, as will now be described,

through the meshing of the slidable pinion 93 thereon with the large gear 95 keyed to the spindle.

Since there is another drive connection from the end of the loose sleeve 89 directly to the large gear 95 and the spindle, it is necessary to interlock the hydraulic shifting devices 94, 99 which alternately accomplishv these gear connec-l tions. In the present speed, as has been stated, the pinion is in engagement with the large gear. The construction of these shifting devices for accomplishing these two shifts is identical with the construction of the shifting device 90, for connecting the intermediate shaft 16 with the sleeve 89 on the spindle, in respect to the general valve extend to both of the devices for flow` through the respective interlocks at the appropriate times. is supplied at this time through registry with a radial supply port |62 in the selector valve.

In respect to the conduit connection |6| to both the hydraulic devices 94, 99, which device is effective for gear engagement through device 94 at this time, the fluid must pass through an interlock groove |63 in the plunger 64 of the device 99 throughthe previously described arrangement of conduit connections relative to the groove, this conduit extends `back to the shifting device 94 entering the region of the cylinder One of these conduits namely |6| f at the rear of the head |95 of the plunger |64 for thepurpose of moving the plunger to move the pinion 93' into mesh with the large gear 95 by means of the yoke |66 connecting the plunger and pinion and guided on a stud I 61. For the purpose of exhausting the region of the cylinder at the opposite side of the plunger head, a ccnduit |68 extends to the seventh transverse plane of the valve (same as Figures16 and 27) and communicates with a branch or fork of a pressure relief passageway |69 (connected to the exhaust at this time as will be described later).

The annular grooves |63 on the plunger of the device 94 constituting a part of the interlock, are disaligned from registry at this time preventing fluid pressure ilow through the conduit 6| which controls the fluid 4pressure flow to the cylinder of the hydraulic device 99 which connects the sleeve 89 directly to the large gear.

Another conduit |10 connects the fifth transverse plane of the selector valve with both shifting devices. The annular pressure relief passageway |69 of the transverse section is connected (see Figure 10) with an annular groove or relief passageway |1| in the sixth transverse plane (same as Figures and 26). At this time this groove |1| is in registration with the port of the conduit |12 extending to and passing through an aligned annular interlock groove |63 of the plunger |64 in the device 99 and connecting through conduit |10 to the fifth transverse plane and an l 4transverse plane (see Figures 16 and 27) for a connection lto an annular relief passageway |14, the ninth transverse plane being shown superposed on the seventh transverse plane in- Figure '1 and in the Figures 16 and 27 inasmuch as the grooving and porting in these two sectional planes is identical.

The annular relief passageway |14` is connected to a similar groove |15 in the tenth transverse plane (see Figures 15 and 26) this plane being shown superposed on the sixth plane in Figure '1 and in Figures 15 and 26 since they are precisely the same. A conduit |16 extends from the tenth plane to the device 94, this conduit being cut off from its connection to conduit |6| by the piston of the shifted device 94. 'I'he other conduit `namely |11, extending from the head end of the cylinder of the device 99, extends directly to the I'device 94 and is cut ofi. by the plunger |64 thereof. The eighth transverse plane of the 4Vvalve includes a supply groove |18 fed from the main control valve 63 through conduit I|2 when the clutch is out for supplying the appropriate ends of the cylinders of the last mentioned two hydraulic devices 94, 99 to move the respective gears out of mesh for the seventeenth or neutral position as will be set forth hereinafter.

'Ihe eleventh transverse plane (see Figures 18 and 29) shows the main supply intake ports and passageway ||3 extending from the valve casing 40 through groove |2| through the rotatable element 4| and the detent |23 via portsl |22 to the interior or main supply chamber of the valve, this passageway H8 being connected to the supply through the' main control valve 63 when the clutchis in for either direction of drive. The tlrst transverse plane which has also been shown in thediagrammatic views ,has no connections shown thereto but includes the ports |29 for exhausting the common exhaust groove |28 present in the rst five planes, the exhaust taking place through the radial ports extending vfrom a completely circumferentially` extended 'portion of the exhaust groove |28 in the valve element for discharging'into the interiorof the the supply can pass around the plunger of the idle .device when the annular grooves are properly aligned, these grooves only being aligned when the gear moved by the respective plunger is out of mesh.

, Neutral or free spindle transmission position Assuming that from the low speed position the operator Wishes to place the transmission ln seventeenth or neutral position in order to permit easy manipulation of the `face plate 12, the

, dial is then turned in anti-clockwise direction the rotative distance of one tooth or one speed change as indicated on the dial. Thereupon the `various ports and grooves of the valve assume the. positions of registry indicated in Figures'fand 9,

and Figures 11 to 19 inclusive.

In respect to the seventeenth or neutral position, the developed view (see Figure 10) of the valve has been spread from the diametric line containing the main ports and passageways which control this position. When this diametric linev or longitudinal central plane is vertically positioned as shown in Figures 8 and 9 of the drawings, the various connections arefunctioning for neutralizing the entire transmission. All the conduit connections extending from the selector valve to the various shifting devices (sectional views to I8 inclusive) are then connected to the common exhaust groove in the rotatable element of the selector valve, thus exhausting all conduits extending to the shifting devices which might supply'gear engaging fluid pressure. The sectional views l to i1 inclusive show the transverse planes ofv the valve which contain grooves K i controlling the shifting operation for free spindle position. y

It occurs, in moving from low to neutral position, that a number of the gears may be left in gear engagement, but due tothe particular positioning ofthe grooving in the valve as hereinafter described, it is positively provided that either one of the gears 93, 96 connecting the-intermediate shaft 16 to the spindle shaft 1| or connecting the loose sleeve 89 directly to the spindle shaft is wihdrawn from meshed position and the spindle left free to` rotate easily without the nercessity of moving back Vgearing when the face plate is manipulated.

' speed position the conduit |33 in the second plane This conduit |33 now registers with a fork oi' `the exhaust groove |28 which is of a circumferential length suitable for exhausting the four circumferentially successively arranged conduits In the previous or lowf |38, |48, |49. |48 simultaneously. Likewise, the conduit |34 extending from device 80 to the third transverse plane or Figure 12 which conduit has previously been a fluid pressure supply connection, is now connected with the common exhaust groove |28. Y

In ,theV fourthtransverse plane or Figure13 Where the conduit |51 had previously been supplied with fluid under pressure`for shifting the gear 88a" of the gear cluster 88 on the sleeve 89 of the spindle into mesh with the small gear ss eathe intermediate shaft 16,1;his eenden |51 is now connected to the main'exhaust groove |28.

. The conduit |6| extending-from the fifth trans- (see Figure 15) through a break, for the present4 position, in the lannular relief grooves |11, |15 of these planea-the conduits |12, |18, extending from the respective planes to the respective hydraulic shifting devices controlling the last two cutoff and rendered inoperative. Forlthis neutral or seventeenth position the conduits |88, |13, entering the seventh and ninth transverse planes (see Figure 16) are supplied from the main supply conduit ||2 extending to the eighth trans- -verse plane from the main control valve 83. The

circumferential groove |18 in the eighth planeor Figure 1'7 connects with a longitudinal groove 4s'hiftable gears 93,'98, in the train, are totally which extends to the next adjacent planes at each side (see Figure 16).

Tracing the conduit |68 which extends from the seventh transverse plane (see Figure 16), it'v will be noted that it supplies the forward `end of the cylinder oi. the hydraulic shifting device r9|! for moving the pinion gear 93 out of mesh with the large gear 95 on the-spindle, this gear having been in mesh in the preceding low speed position. Y

The conduit |13 extending from the ninth transverse plane (see Figure 16), extends to and supplies the rear end of the cylinder of the hydraulic device 99. It occurs in the present shifting sequence thatthe plunger of this last mentioned device 99 is not moved by this last connecti'on since it had been previously held in unmeshed position. The purpose of the seventeenth position, as will be apparent from the above connections is to absolutely move both the pinion gear 93 and thelgear 98 out of engagement so that the spindle is entirely free from any gear connection. Therefore, it will be seen that after the operator has set the dial to indicate seventeenth or neutral position, the clutch being out, the immediate eilect is to deliver fluid from the main supply line |08 'extending from the pump to the control valve 83, thence through the conduit ||2 to the selector valve and through the conduits |68, |13, extending from the selector valve to the respective ends of the cylinderslrnenthe clutch lever is moved to connect the power,

the shiftingvoperation occurring automatically in the first phase of throw-in movement of the clutch lever. The interlock between the hydrau-f lic sluiting devices concerned in the total disengagement of the spindle is rendered inoperative by positioning the dial in seventeenth position since` at this time it is of no importance. To this purpose, the conduits |6|, |10, extending between lthe respective shifting devices and adaptedto be connected with conduits on the opposite sides of the respective devices, are registered with the circumferential groove of the common exhaust passage |28 in the fifth transverse plane.

Figure 31 of the drawings has been enlarged out of the neutral or 'free spindle position layout (Figure 8) for the purpose of clearly showing the interlock for preventing'shifting of one connection to the large-gear on the spindle While the other connection to the"spind1e is in or Avice versa. It will be observed from this view that the exhaust for the inner end of the hydraulically operated shifting device 94 which is being moved from position of gear mesh `to position of gear unmesh, takes place throug the conduit 16| extending through the annular interlock groove of the device 99 which holds its gear out of mesh, thence to the exhaust groove |28 in the fifth transverse plane of the selector valve and to the exterior for return to the sump. The only supply conduits in this position are those conduits |12, |16, which extend fromf the seventh and ninth transverse planes to the cylinders, the remainder either containing dead uid or uid being exhausted.

Extreme high speed transmission position series are reversed.- As shown in the secondv transverse plane of the selector valve, one, namely |48, ofthe four conduits, allof which had previously been exhausted, registers with a radially disposed uid supply port |32. This conduit |48 extends to the interlock of the shiftingdevice 19 for passage, after the device 19 has been moved into balanced or neutral position, to the shifting device for shifting the same.

Thesections of the conduit |48 are connected through the annular groove vof the interlock plunger which is rst balanced asV hereinafter described, and the fluid supplythen proceeds to the device 80 to be shifted and supplies the pressure between the floating or balancing piston |31 and the end of the shifting plunger |38 in the appropriate cylinder |36 of the device 80 for moying the large gear cluster'18 to mesh the large gear 18b thereof with the -small gear 8| on the intermediate shaft 16.-

'I'he forked conduit |44 ofthe device 19, which is to be balanced at this time, is connected through a port |35 in the third transverse plane to the main supply chamber in the interior of the valve forbringing the balancing pistons |31|31 toward each other and against the respective ends of the shifting plunger |38 for effecting the balanced or neutral condition of the shifting device 19. Also boththoseconduits |33, |46, which extend through the respective interlock grooves |42 of the shifting device 89, or the one\ about to be shifted, and which accomplish the shifting of the shifting device 19 in reverse directions are open -tct exhaust-by way of the exhaust groove |28 in the second transverse plane.

At this time the opposite end of the/cylinder |36 at the opposite end of the shifting plunger |38 of device 80 has the region thereof at the inner side of the oating piston |31 exhausted by way of the conduit |49, through interlock groove |42 of device 19, to the second transverse plane and the main exhaust groove |28. Both the floating pistons |31 of the device 80 being shifted at this time are free tomove in view of the fact that their respective cylinders |36 are exhausted on the side toward which they are moved by way of the forked"v passageway |34 which extends to' this same time is the disengagement of the large the spindle from the small gear 86 and the meshing of the small gear 88b of this cluster with a gear 8| of the cluster of four on the intermediate shaft 16. For the accomplishment of this change the hydraulicshifting device connected to this Y gear cluster'is reversed as to position by reversing the supply and exhaust thereto.

The conduit |51 which in low speed position gear 88u of the lcluster 88 splined on the sleeve of supplies fluid pressure to the rear side ofthe plunger head is now eifectivefor exhausting from this Jside by way of the main exhaust passage |28 in the fourth transverse plane, whereas the previously exhausted conduit |59 is now effective. for supplying fluid pressure through connection with the main supply chamber within the valve by way of a radial port |58 in the fourth trans-y verse plane. Thus the lowest possible speed is imparted to the spindle sleeve 89 and the inter mediate shaft 16 whereby the drive can either be taken `from the`sleeve- 89 or from the intermediate shaft 16 to the spindle shaft.

In the high speed position, the drive is taken directly from the sleeve 89 to the spindle 1| by way of the gear 96 in splined connection on the hub of the-large gear 95. The slidable internally toothed element on the hub of .the gear is meshed with the gear 91 secured on the end of the sleeve by itsshifting device 99. For this purpose, the supply is from the center of the selector valve through a radial port in the fifth transverse plane, thence to the registering conduit |10 to the interlock of device 94, which moves the pinion 93, through this interlockgroove in ViewA of 'the disengaged condition of the gear 93 and proper position of the hydraulic shifting device 94, thence by wayof the conduit |11 tothe head end ofthe plunger |64 in the hydraulic device 99 whereupon the plunger is moved for effecting shifting of the internal gear 96 and meshing thereof with gear 91. g' The opposite end of the cylinder of shifting device ss 1s exhausted by way of the conduit |13 draulic shifting device 19 of `this interlocked apparent in following the course of uid pressure and exhaust at this position of the valve. It will be noticed that the conduit |68 which extends to the head end of this hydraulic shifting device 94 connects to the seventh sectional plane -of the valve where connection is had with the annular groove |69 in the valve element; thence connected overone plane to the sixth sectional plane; thence by way of conduit |12 to the plunger of the hydraulic sluiting device 99 which has -just been shifted and then ineffective for further passage in view of the disalignment of the interlock groove |63 at this point. The oil, therefore, in the head end of the cylinder is dead or trapped, and therefore, still effective for holding the plunger |64 in its shifted position.

The other end of the cylinder of device 94 has been exhausted through conduit |6| which extends to the interlock inlet of the hydraulic device 99 just shifted where it also is cut off due to displacement of the particular interlock annular groove |63. It will be observed, therefore, that the fluid is either under pressure in the system directly from the pump, or it is being exhausted or is trapped or considered as dead oil,

the latter condition being effective for holding those parts, Awhich it has previously moved, in set position.

Valve port arrangement 'Referring first to those views showing the second to fifth sectional planes inclusive of the valve, it will be noted that the radial ports and exhaust grooving is regular with the exception of onepo-rtion inl,the'circumference of the valve, this portion being added for the purpose of the seventeenth position. The sixth to tenth sectional planes of the valve-include annular grooves in the movable element extending substantially all the way around the Valve with the exception lof the eighth Vplanefor interconnecting the passageways effecting seventeenth position during the sixteen speed changes and this grcoving only being effective for delivering fluid pressure at one position of the selector valve, namely the seventeenth.

Referring back to the description wherein it is stated that the supply porting and exhausting y grooving is regular with the named exceptionf it will be seen that in the second sectional plane, if the valve is successively moved anti-clockwise from high speed position, counting the high speed position, a supply port |32 will be connected to.

the four conduits |33, |46, |49, |48 extending from this plane in succession with the exhaust effective for the other three. 'I'he -high speed position which has just been described places the largest gear I6b on the first shaft 'l5 of thel transmission in mesh with the small gear -8| of the cluster of four on the intermediate shaft 16.

Moving the radial supply port4 to the next conduit by anti-clockwise movement, the supply is delivered to the opposite end of the first shifting device 80 of the mechanism for moving the second largest gear `|8=ion the rst shaft into mesh with its component gear on the intermediate shaft 16, the opposite end of the cylinder of the hydraulic device being exhausted at this time.

During these two, speed changes which are the highest and the next to the highest, the fluid pressure supply has been constant to the hygroup, for balancing the same, throughtwo successively registering supply ports' |35 in the third plane registering with the supply conduit |44 extending to the mentioned shifting device. This condition will be reversed upon-a third dial movement, and the pair of supply ports will register successively with the conduit |34 in the third transverse plane for operating to balance the -previously operated shifting device 89, whereas fthe alignment of the supply port |32 in the second transverse plane with the next two succeeding conduits |46, |33, will effect shifting of the hydraulic shifting device 19 in reverse directions.

This cycle of four shifts' will be repeated four times inthe rotation of the valve, as will readily be apparent, due to the regular arrangement :of the ports as described.

During these first four high speed changes, the

porting arrangement in the fourth transverse changes on the rst shaft, the hydraulic shiftingU device 96 is in one position, and for the next four in reverse position. 'I'hen on the third series of section, alternately, and simultaneous exhaust--V ing of they one not being supplied.

Therefore, considering the shifts in groups of four as effected on the -rst four gears'of the train, the hydraulic shifting device 99 will be asl maintained in one position and likewise the shift- -ing devices 94, 99 controlling the pinion 93 and gear 96 on the spindle shaft. For the next four, the position of the hydraulic shifting device 90 will be reversed whereas the devices 94, 99.- controlling the pinion 93 and the internal' gear 96 will remain as for the first four. For the third four, the hydraulic device 90 will be returned to, original position, whereas the shifting devices 94, 99, controlling the -pinion and internal gear will be reversed as to meshed position. For the last four, the hydraulic device 90 Will again be reversed,v whereas the shifting devices 94, 99, will remain the same.

The hydraulic gear shifting apparatus and its various controls are adaptable for use in conjunction with any style of lathe for controlling the speed of rotation of the spindle. Thecontrolling means may readily cocperate with standard ,l

l.. In a hydraulic gear shifting Asystem for a .v

lathe, a spindle, a transmission for driving said spindle, a selector valve, a fluid' pressure supply means for said selector valve, shifting devices associated with the respective shiftable gears of the transmission and having fluid connections to said selector valve for a plurality of speed changes, and means included in ysaid selector valve and shifting devices for entirely disconnecting the spindle shaft from the remainder of the transmission at one position `of the selector valve.

2. In a hydraulic gear shifting system for a lathea spindle, a clutch controlled transmission for driving said spindle of a lathe, a selector valve, a fluid pressure supply means for said selector valve controlled by the clutch actuation, shifting devices associated with the respective shiftable gears of the transmission and having fluid connections to said selector valve fora plurality of speed changes, and means included in said selector valve and shiftingdevices for entirely disconnecting 'the spindle shaft from the remainder of the transmission at one position of the selector valve, said means effective when the clutch is out.

3. A hydraulic apparatus for shifting the gears of a lathe, a clutch, an operating lever for said clutch, a fluid pressure means, a main control valve, shifting devices associated with the respective shiftable gears; a selector valve for controlling the uid supply from the main'controlvalve to the respective devices, said control valve operatively connected to the operating lever of the clutch and connecting the fluid pressure supply .to the selector valve when the clutch is'in for connecting the ijluid pressure to the shifting devices for a gear shift.

4. In a hydraulic gear shifting apparatus for a lathe, a spindle shaft, a transmission for driving said spindle shaft, a fluid pressure means, a selector valve, shifting devices for the respective gears of the train, fluid connections between the selector valve and the respective devices, said selector valve having passageways therein for effecting a -plurality of gear shift positions and for totally disconnecting all the gears of the train from the spindle shaft for free spindle movement when manipulation of the face plate on the spindle shaft is necessary.

5. In combination with the headstock, bed and carriage of a lathe; a hydraulic apparatus for shifting gears within the headstock, comprising, fluid pressure means within the headstock, a selecto'.` valve, a uid connection from said pressure means to said selector valve, fluid actuated devices for the respective gears connectedto and controlled by the selector valve for appropriately shifting the gears, and a dual control for operating the selector valve including a manipulating means on the headstock and a manipulating means on the carriage, the latter flexibly 'connected to the headstock. A

' 6.'.In a hydraulic apparatus for shifting the gears of a lathe, speed change gearing, a clutch for controlling said gearing, an operating lever for the clutch, a fluid pressure means, a main control valve, fluid connection between said control valve-and pressure means, a plurality of shifting devices associated with the respective gears, a selector valve having fluid connections to the shifting devices for lcontrolling the fluid supply from the main control valve to the respective devices, said control valve `operatively connected to the operating lever of the clutch and connecting the fluid pressure supply to the selector valve in either ,in or out position of tlie clutch for respectlvely connecting the fluid pressure for a gear shift or for a neutral position.

1. In a lathe, a headstock, a spindle, a transmission for driving said spindleincluding asleeve loosely rotatably mounted on said spindle adjacent one bearing thereof, said sleeve having a gear at the end adjacent said bearing and a clutch element formed on its other end, a gear fixed to the spindle adjacent the other bearing thereof, means for rotating said sleeve, a clutch element splined to said flxed gear and adapted to cooperate with the clutchlelement forme/i on the end of the sleeve, and a back gearing meshing with the gear on vthe sleeve adjacent the bearing and adapted to be meshed with the xed gear whereby drive may be imparted to the spindle from the sleeve either through the back gearing or through direct connection'toI the flxed gear through the splined gear.

' 8. In a hydraulic gear shifting system for shifting the gears Within the headstock of a lathe, a speed change transmission, a clutch for said transmission, a control lever for said clutch, a fluid pressure developing means, a selector valve, a f'luid'connection between said fluid pressure developing means and said selector valve, a main control valve in said fluid connection adapted to be actuated by the clutch lever for admitting the fluid pressure to the selector valve when the clutch is in, shifting devices located adjacent the respective shiftable gears including hydraulically i moved plungers, fluid connections between the selector valveand the respective shifting devices for supply/ and exhaust thereto, means for manipulating said selector valve for controlling the passage of the fluid pressure to the respective shifting devices, and a hydraulically operated detent mounted Within the selector valve for locking nections between the selector valve and the respective shifting devices for supply and exhaust thereto, means for manipulating said selector valve for selectively controlling the passage of the fluid pressureto the respective shifting devices, and a hydraulically. operated detent mounted within the selector valve for locking the same in set position when the fluid pressure is admltted. 10. In a hydraulic gear shifting system for shifting the gears in the headstock of a lathe, a fluid pressure means, hydraulically actuated shifting devices disposed within the headstock for shifting the slidable gears of the train, a selector valve having fluid connection with said fluid pressure means, fluid connections between the selector valve and the respective hydraulically operated shifting devices, said selector valve including a casing-,to which said fluid connections are radially attached, and a hollow manually rotatable valve element including radial ports for admitting the fluid pressure to the interior thereof and selectively admitting the fluid pressure from the interior to the various supply connections to the hydraulically operated shifting devices, said casing having an exhaust port, andb .said rotatable valve element having exhaust grooves in its periphery in constant connection with said exhaust portselectivel'y registered with the fluid connections for exhausting the shifting devices. Y

1l. In a hydraulic apparatus for shifting the 

